The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/122135f99d0901b4fe14eba13acc10df34d7b99e

commit 122135f99d0901b4fe14eba13acc10df34d7b99e
Author: Takumi Fujimoto <takumif@chromium.org>
Date: Wed Jun 20 20:27:33 2018

[Harmony Cast Dialog] Select the active sink when opening dialog

When the sink list goes from empty to non-empty, we select the first
sink with a media route, so that if the user wants to terminate the
route, they can do so with just one click on the "Stop" button.

Bug:  851586 
Change-Id: I6a6309de0ef577ffe4e3dbf3537a748695e555d3
Reviewed-on: https://chromium-review.googlesource.com/1103453
Reviewed-by: mark a. foltz <mfoltz@chromium.org>
Commit-Queue: Takumi Fujimoto <takumif@chromium.org>
Cr-Commit-Position: refs/heads/master@{#568984}
[modify] https://crrev.com/122135f99d0901b4fe14eba13acc10df34d7b99e/chrome/browser/ui/media_router/cast_dialog_controller.h
[modify] https://crrev.com/122135f99d0901b4fe14eba13acc10df34d7b99e/chrome/browser/ui/media_router/cast_dialog_model.cc
[modify] https://crrev.com/122135f99d0901b4fe14eba13acc10df34d7b99e/chrome/browser/ui/media_router/cast_dialog_model.h
[modify] https://crrev.com/122135f99d0901b4fe14eba13acc10df34d7b99e/chrome/browser/ui/views/media_router/cast_dialog_view.cc
[modify] https://crrev.com/122135f99d0901b4fe14eba13acc10df34d7b99e/chrome/browser/ui/views/media_router/cast_dialog_view.h
[modify] https://crrev.com/122135f99d0901b4fe14eba13acc10df34d7b99e/chrome/browser/ui/views/media_router/cast_dialog_view_unittest.cc
[modify] https://crrev.com/122135f99d0901b4fe14eba13acc10df34d7b99e/chrome/browser/ui/views/media_router/media_router_views_ui.cc
[modify] https://crrev.com/122135f99d0901b4fe14eba13acc10df34d7b99e/chrome/browser/ui/views/media_router/media_router_views_ui_unittest.cc